Wireless networks, such as infrastructure mode wireless networks based on Institute of Electrical & Electronics Engineers (IEEE) Standard 802.11, allow wireless client devices to establish communication connections to the wireless network via wireless network access points. Each wireless network access point, or access point, provides wireless network connectivity to wireless client devices within radio communication range of the access point. Due to limitations on the transmission/reception range, or coverage area, of individual access points, a wireless network may use multiple access points within an operational environment, such as a single building or multi-building campus. By overlapping the coverage areas of multiple access points, network engineers attempt to provide wireless client devices, at any location within the operational environment, with at least one access point with sufficient signal strength to support a reliable connection to the wireless network.
On starting up, a wireless client device scans its surrounding operational environment to identify one or more access points with sufficient signal strength at the wireless client device's location to support reliable communication. The wireless client device may establish a wireless network connection, or communication link, via the access point with the strongest signal. Once a wireless network connection is established, should a link quality of the communication link degrade, e.g., due to the wireless client device physically moving to another location within the operational environment, the wireless client device may initiate a subsequent scan of the operational environment to identify another access point with greater signal strength at the new location and, therefore, capable of providing a communication link with improved link quality. This process continues for as long as the wireless client device is within the operational environment supported by the wireless network and wishes to maintain a wireless network connection.
Some obstacles within an operational environment, such as iron girders, fireproofed stairwells, thick masonry walls, and/or rooms with electromagnetic shields, for example, may block access point signals. Such obstacles are typically taken into account in the design of a properly designed wireless network by strategically positioning a sufficient number of access points so that such blocked areas are covered by at least one other access point. However, a sudden and severe reduction in the signal strength of an access point caused by such obstacles can adversely affect the wireless network connections of wireless client devices traveling through the operational environment while connected to the wireless network via the blocked access point. For example, such a reduction in signal strength may result in a loss of the wireless network connection before access to the wireless network via an alternate access point can be established.